From: David S. <ds...@al...> - 2002-09-13 22:48:44
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John Levon wrote: > > My biggest concern about all this is simply interpretation. How can we > present this data to the user in a useful way ? No arc information is > present, meaning that the user must apply his knowledge of the source to > work out the most likely "user" of stack samples. I'd be interested in > people's ideas here. > Just presenting it "as is" would be useful even without arch info. For example, this is the result from a small test program with main() which calls four functions testf1()-testf4(). The percentage in the backtrace column is calculated as samples/total no of interrupts and shows how much time is spent in that function including children. Note that main() + bash + default_idle ~ 100% (meaning that all time is spent *somewhere* :) The point is, I think this *is* useful information. Arc information would be even better, but this is useful at it is. EIP Backtrace %-age %-age symbol name image name 0 93.404 __libc_start_main test-max-static 0 93.404 main test-max-static 0 93.404 _start test-max-static 5.74196 46.352 testf4(int, String const &, char *) test-max-static 20.4364 22.6 testf1(int, String const &, char *) test-max-static 21.9043 17.548 chunk_alloc test-max-static 16.2173 12.992 testf2(int, String const &, char *) test-max-static 11.8983 9.532 chunk_free test-max-static 0 6.076 start_kernel vmlinux 0 6.076 cpu_idle vmlinux 0 6.076 L6 vmlinux 7.55942 6.056 default_idle vmlinux 6.79049 5.44 String::data(void) const test-max-static 6.67565 5.348 String::len(void) const test-max-static 0.399441 3.548 testf3(int, String const &, char *) test-max-static 0.034951 1.62 (no symbol) bash ... etc ... /David |